Process catalysed by bis-trifilmide compounds

ABSTRACT

A process for carrying out a chemical reaction which is catalysed by one or more metal or hydrogen fluoroalkyl-sulfonylated compound which process comprises carrying out said reaction in the presence of an ionic liquid or in solvent-free conditions.

The present invention relates to a process for carrying out a chemicalreaction which is catalysed by bis-triflimide and relatedbis-trifilimide compounds. More specifically, the present inventionrelates a process for carrying out such chemical reactions in thepresence of an ionic liquid or in solvent-free conditions.

The catalysis of chemical reactions is of major importance in chemistry.The salts of certain metals are known to act as Lewis acids (electronpair acceptors), which interact with the reactants (and products) of areaction, producing a reaction rate enhancement and/or selectivityenhancement. Also salts of metals which can exist in variable oxidationstates (such as transition metals) are known to catalyse chemicalreactions such as Friedel-Crafts, oxidation, reduction, Diels-Alder,isomerisation, coupling, addition and elimination reactions. TheFriedel-Crafts reaction is often used to functionalise aromatic rings.The reaction involves the interaction of an acylating or alkylatingagent such as benzoyl chloride or benzyl chloride with an aromaticcompound such as benzene to give the products, in this case,benzophenone and diphenylmethane. The reaction requires a Lewis acidcatalyst such as aluminium(III) chloride. The reaction suffers from amajor disadvantage in that, particularly with acylation reactions, atleast one molar equivalent of Lewis acid catalyst is needed. The work-upof these reactions results in the destruction of the catalyst and canproduce considerable amounts of acidic aqueous waste. There is a needfor an improved catalyst system which requires less catalyst, producesless waste and allows for the catalyst to be reused and recycled.

Metal bis-triflimides are known as catalysts for some reactions.Examples include polymerisation of styrene with titanium (or zirconium)bis-triflimides in the solvent toluene. Magnesium bis-triflimide hasbeen used for the reaction of silyl-enol ethers or silyl-ketene acetalswith allylic or benzylic acetates in the solvent dichloromethane.Scandium bis-triflimide has been used as a catalyst for the formation ofacetals and ketals from carbonyl compounds (or enol ethers) in thesolvent dichloromethane. Aluminium, ytterbium and titaniumbis-triflimides have been used in the reaction of acetic anhydride withanisole or diphenyl ether to give acetyl anisole or4-phenoxyacetophenone respectively. These reactions are carried out inthe dangerous and explosive solvent, nitromethane. Such a procedure isof very limited benefit as aromatics less reactive than anisole wouldrequire elevated reaction temperatures and can only be carried out on asmall scale due to the inherent explosion risk. There is therefore aneed for a reaction system that does not require the use of explosivesolvents such as nitromethane or toxic solvents such as toluene ordichloromethane.

The present invention solves the problems of the prior art by providinga process for carrying out a chemical reaction which is catalysed by oneor more metal or hydrogen fluoralkylsulfonated compound which processcomprises carrying out said reaction in the presence of an ionic liquidor in solvent-free conditions.

Suitably the chemical reaction is an aromatic electrophillicsubstitution reaction such as the reaction of an aromatic compound andan alkylating, acylating or sulfonating agent to give an arylalkane,aryl ketone or sulfone. The reaction may be a Friedel-Crafts acylation,Friedel-Crafts alkylation or a sulfonylation. The reaction may be thereaction of acid halides, anhydrides or carboxylic acids with aromaticcompounds to give an aryl ketone. The reaction can be a reaction ofsulfonyl halides, sulfonic anhydrides or sulfonic acids with aromaticcompounds to give a sulfone. The reaction may be a reaction of alkeneswith aromatic compounds to give aryl alkanes. The reaction may also be abis-triflimide compound catalysed or promoted isomerisation,polymerisation or rearrangement of chemical compounds or molecules. Thereaction may be a rearrangement of esters of phenols to acyl phenols(Fries rearrangement). The reaction may be a dimerisation (oroligiomerisation or polymerisation) of alkenes to give dimerised alkenes(or oligomerised or polymerised alkenes). The reaction can be themigration or isomerisation of carbon-carbon double bonds in unsaturatedcompounds. The reaction can be an hydration, nitration, carbon-carbonbond forming reaction, halogenation, oxidation or reduction reaction. Ageneral reaction scheme for the reactions catalysed using metalbis-triflimides is shown below:

where Ar=aromatic group, R=alkyl, acyl, alkylsulfonyl, arylsulfonyl.X=Cl, OH, Br, I, F, OR, SH, NR₂, OSO₂R, O₂CR or other leaving group.

By metal or hydrogen fluoroalkylsulfonylated compound is mea a compoundderived from a metal or hydrogen cation and [N(SO₂C_(x)F_((2x+1)))₂]⁻anion. For example, the catalyst can be any compound containing a metaland a fluorinated-alkylsulfonylated anion (preferably afluorinated-alkylsulfonylamine anion). The one or more metal or hydrogenfluoroalkylsulfonylated compound is preferably a metal or hydrogenbistriflimide. By bis-triflimide compound is meant any compound whichcomprises the ion [N(SO₂CF₃)₂]⁻. This ion is commonly known by thefollowing names: triflimide, bis(trifluoromethanesulfonyl)amide,bis-trifluoromethanesulfonimide, bis(trifluoromethanesulfonyl)imide,trifluoromethanesulfonimide. In this document, the term bis-triflimidewill be used as the name for the [N(SO₂CF₃)₂]⁻ ion. Also, theabbreviation [NTf₂] is sometimes used to represent the [N(SO₂CF₃)₂]⁻ion. Preferably the bis-triflimide compound is a metal bis-triflimidecatalyst or hydrogen bis-triflimide HN(SO₂CF₃)₂. The formula of thehydrogen and metal bistriflimide catalyst isM_(x) ^(n+)[{N(SO₂CF₃}₂)_((nx-yz))]^((nx-yz)−)Ly^(z−)where M is a hydrogen or a metal;L is a negative or neutral ligand;n is 2, 3, 4, 5, 6, 7 or 8;x is greater than or equal to 1y is 0, 1, 2, 3, 4, 5, 6, 7 or 8; andz is 0, 1, 2, 3 or 4.

M may represent more than one type of metal ion. M is preferably a metalselected from the metals in groups 1 to 16 of the periodic table and thelanthanides and the actinides. By group 8 is meant the group containingFe, Ru, Os, Hs, by group 9 is meant the group containing Co, Rh, Ir, Mt,etc. L may be selected from oxos (such as VO²⁺), phosphines (such astriphenylphosphine), water, halides or ketones. The ligand may originatefrom a solvent, reagent or by-product in the reaction mixture for makingthe catalyst or the reaction mixture in which the catalyst is used.

The metal or metals may possess one or more neutral or negative ligands(such as triphenylphosphine or oxo (such as in VO₂ ⁺)) or any otherligand such as as oxo, phosphines, water, halide or ketones. Preferablythe metal or metals are preferably, but not exclusively, a transitionmetal, lanthanide or actinide, group 2 (Be, Mg, Ca, Sr, Ba), Group 11(Cu, Ag, Au), Group 12 (Zn, Cd, Hg) Group 13 (B, Al, Ga, In, Tl), Group14 (Si, Ge, Sn, Pb), Group 15 (P, As, Sb, Bi), Group 16 (S, Se, Te, Po).Preferably the metal or metals are preferably, but not exclusively inthe +2 oxidation state (eg Co²⁺), in the +3 oxidation state (eg Al³⁺) orin the +4 oxidation state (eg Ce⁴⁺). Cationic species containing chargedligands could also be used (eg UO₂ ²⁺, VO²⁺). Monovalent, pentavalent,heptavalent and hexavalent cationic species may also be used.Particularly preferred metal bis-triflimide compounds which have beenprepared and isolated for use in the catalytic reactions of the presentinvention include magnesium bis-triflimide, calcium bis-triflimide,strontium bis-triflimide, barium bis-triflimide, aluminiumbis-triflimide, gallium bis-triflimide, indium bis-triflimide, scandiumbis-triflimide, yttrium bis-triflimide, lanthanum bis-triflimide, ceriumbis-triflimide, ytterbium bis-triflimide, chromium bis-triflimide,manganese bis-triflimide, iron bis-triflimide, cobalt bis-triflimide,nickel bis-triflimide, copper bis-triflimide, zinc bis-triflimide,silver bis-triflimide, cadmium bis-triflimide, tin bis-triflimide, leadbis-triflimide, and bismuth bis-triflimide.

Typically, the reactions of the present invention require an amount ofbis-triflimide compound is between 0.000001 and 1000 mol %, typicallythis is between 0.1 and 10 mol %, preferably it is between 0.5 and 5 mol% and more preferably this is between between 0.5 and 2 mol %.

The process may involve the addition of the bis-triflimide catalyst tothe reactants, e.g. the addition of 1 mol % of Zn(NTf₂)₂ to a mixture ofan alkylating agent or acylating agent or sulfonylating agent andaromatic compound. This can be carried out either in the presence of anionic liquid or in solvent-free conditions. When carried out in thepresence of an ionic liquid, the catalyst may be dissolved or suspendedin an ionic liquid. An ionic liquid is a molten salt that is in a liquidstate at the reaction temperature and usually (but not essentially)molten at or near room temperature, i.e, 20° C. When carried out insolvent-free conditions, the catalyst may be soluble, or partiallysoluble, in the reactants or products (these can act as both solvent andreagent). The products can be separated from the catalyst at the end ofthe reaction by distillation or solvent extraction with a solvent thatthe catalyst is insoluble in (for example cyclohexane).

An ionic liquid is a molten salt or mixture of salts that is in theliquid state at the temperature of the reaction. The ionic liquids (ifused) are preferably molten salts that are in the liquid state atambient temperatures, and preferentially dissolve the catalyst whencontacted with the reagents. Preferably the catalyst is soluble in theionic liquid to a much greater extent that the products and/or reactantsduring the separation of the catalyst from the products/reactants. Theionic liquid consists of two components, which are a positively chargedcation and a negatively charged anion. Preferably the cation is anorganic cation and the anion is an organic or inorganic anion. Thatcation for the process is preferably a 1-alkylpyridinium (such as1-hexylpyridinium) or 1,3-dialkylimidazolium cation such as1-butyl-3-methylimidazolium [bmim] or 1-ethyl-3-methylimidazolium[emim]. Other cations for this process are other alkyl- orpoly-alkylpyridinium, alkyl or poly-alkylimidazolium, alkyl orpoly-alkylpyrazolium, alkyl or poly-alkyl ammonium, alkyl or poly-alkylphosphonium, other ammonium, phosphonium cations, alkylateddiazabicyclo-[5,4,0]-undec-7-ene and related cations, or any othercation that gives rise to compounds termed ionic liquids. The anion forthe process is preferably one that is stable to chemical alterationduring the reaction and imparts desirable physical characteristics tothe ionic liquid. Some suitable anions for the ionic liquid arebis-trifluoromethanesulfonimide, bis-pentafluoroethanesulfonimide,hexafluorophosphate(V), tetrafluoroborate(III),trifluoromethanesulfonate, cyanamide, fluoro or perfluoroalkylsulfonate,halide, sulfate, hydrogensulfate, alkylsulfate, alkylsulfonate,arylsulfate, arylsulfonate, nitrate, carboxylate, phosphate,hydrogenphosphate, dihydrogenphosphate, alkylphosphate,alkylphosphonate, phosphonate, nitrite, arsenate, antimonate,haloaluminate, aluminate, borate, silicate, haloindate(III), gallate,alkylborate, halogallate or any other anion that gives rise to an ionicliquid.

Examples of ionic liquids are given below:

Preferably the ionic liquid or the catalyst or the ionic liquid andcatalyst combination is insoluble in low- or non-polar organic solventssuch as diethyl ether or hexane.

In addition to ionic liquids being excellent media for the execution ofthe Friedel-Crafts and other reactions, a second major benefit of thisinvention is that the catalyst and ionic liquid can be recycled andreused in many reactions. This means that catalysts are not lost. Thisis an improvement over reactions performed in nitromethane, which is anexplosive solvent and is hard to recycle.

The chemical reactions of the present invention may be carried out attemperatures between temperatures of from −100° C. to 450° C. Preferablythe reaction is performed at a temperature between 20° C. and theboiling point of the reactants.

The present invention further provides a process whereby thebis-triflimide catalyst or related fluoroalkylsulfonylated compound maybe generated in situ by the addition of a metal or a metal compound (forexample, a metal halide) to a bis-triflimide salt (or otherbis-triflimide compound) or related fluoroalkylsulfonylated compound.This process can be carried out in the absence of a solvent or in anionic liquid. An example of this would be the addition of a metal saltto a bis-triflimide ionic liquid (or hydrogen bis-triflimide to an ionicliquid) to generate a catalyst that is capable of catalysing the desiredchemical reaction. This can be achieved by taking a metal or metalcompound, not necessarily a bis-triflimide salt (for example a metalhalide such as, ZnCl₂ or SnCl₄), and dissolving (reacting) it in abis-triflimide ionic liquid or other source of bis-triflimide (forexample, HN(SO₂CF₃)₂). A suitable source of bis-triflimide ions is[emim] [NTf₂]. To this combination, the reactants, e.g. alkylating,acylating or sulfonating agent and aromatic compound can be added, withheating if necessary. The products can be separated from the catalyst atthe end of the reaction by distillation or solvent extraction with asolvent in which, for example, the catalyst and ionic liquid combinationare insoluble (for example, cyclohexane).

After the reaction of the present invention, the catalyst may beseparated from the products/remaining reactants. Preferably theseparation process does not destroy the catalyst. When the products ofthe reactions are aryl ketones, alkyl-aromatic compound, or sulfones,these are usually readily separated from the catalyst or ionicliquid/catalyst mixture by several different means as these aregenerally neutral covalent molecules. These are usually (but notnecessarily) neutral covalent molecules, which are. The simplest andpreferred means is vacuum distillation (typically at 1 mm Hg) of theproduct and by-product directly from the reaction vessel (Kugelrohrdistillation is preferred but not essential). The catalyst and ionicliquid, having no measurable vapour pressure, remain in the reactionvessel. The catalyst and/or ionic liquid can be immediately reused uponcooling. A second valuable method for the separation of the ionicliquid/catalyst from the products is solvent extraction. The ionicliquid and catalyst are insoluble in low or non-polar organic solventsor supercritical fluids. The reaction vessel can be washed with asolvent or mixture of solvents such that the product and by-productdissolve in the solvent, whereas the ionic liquid and catalyst remain ina separate solution. The separation can be effected by decantation orother means. Suitable solvents for this separation are alkanes(cyclohexane, hexane, petroleum ether or other alkanes or alkane-likecompounds), aromatics (toluene, benzene, xylene or other compoundscontaining an aromatic group), ethers (such as diethyl ether, dibutylether) or esters (such as ethyl acetate, amyl acetate), supercriticalsolvents, or any other material capable of allowing for the separationof the catalyst (and ionic liquid if present) from the products orreagents. Another method involved azeotropic separation with compoundssuch as steam (for example steam distillation). Some halogenatedsolvents such as dichloromethane or chloroform partially dissolve theionic liquid and catalyst and are therefore of lesser use in thisprocess. Thus the present invention provides a process where the productis easily separated from the catalyst or catalyst/ionic liquidcombination or solvent containing combination by solvent extraction,distillation, vacuum distillation, steam distillation, pervaporation,azeotropic distillation, precipitation, crystallisation, phaseseparation, supercritical fluid extraction or any other non-destructivephysical process. The present invention further provides a process wherethe product is easily separated from the catalyst or catalyst/ionicliquid combination or solvent containing combination by solventextraction using one or more of the following methods: (a) with alkanesor boiling alkanes (eg. cyclohexane at 80° C.), (b) vacuum distillationat pressures preferably between 0.01 mmHg and 10 mmHg, (c) steamdistillation or with the use of superheated steam at temperatures up to500° C., (d) phase separation, (e) supercritical fluid extractionpreferably with carbon dioxide.

The present invention relates to the use of metal bis-triflimides insolvent-free conditions or in ionic liquids. The reactions of aromaticsboth more and less reactive than anisole can be achieved in thisinvention, as well as the reaction of anisole itself. The presentinvention also provides a method of generating the catalyst in situ thusobviating the need to isolate the metal bis-triflimide catalyst andsimplifying the experimental procedure. One of the principal benefits ofthis invention is that the product(s) of the reaction can be easilyseparated from the catalyst and/or ionic liquid-catalyst combination bya physical process such as distillation, steam stripping or by solventextraction with an inert solvent (including supercritical fluids) ormolecular solvents. The ionic liquid and/or the catalyst (which usuallyremains in the ionic liquid during the separation process) can be reusedfor further reactions. Further reactants can simply be added to theionic liquid and/or the catalyst once the previous products/reactantshave been removed.

The present invention is illustrated by the following figures andexamples.

FIG. 1 shows the variation of yield with time in the metalbis-triflimide catalysed reaction of benzoyl chloride with toluene.

FIG. 2 shows the variation of yield with time in the 1% FeCl₃ and 1% Febis-triflimide catalysed reaction of benzoyl chloride with toluene in[bmim] [NTf₂].

FIG. 3 shows the variation of yield with time in the synthesis ofphenyl-4-chlorophenyl sulfone.

FIG. 4 shows the variation of yield with time for five reactioncatalysed by 1 mol % metal chlorides dissolved in [bmim] [NTf₂] for thereaction of toluene with benzoyl chloride to give methyl benzophenone at110° C.

EXAMPLE 1 The Reaction of Toluene with Benzoyl Chloride with Cobalt(II)bis-triflimide Catalyst

Cobalt(II) bis-triflimide (0.13 g, 0.21 mmol) was added to toluene (3.0g, 32.5 mmol) and benzoyl chloride (3.0 g, 21.3 mmol) in a 25 cm³ roundbottomed flask equipped with a magnetic stirrer and reflux condenser.The mixture was heated under reflux for 3 hours (judged to be at least99% complete by gas chromatographic analysis), and cooled to roomtemperature. Petroleum ether (15 cm³, bp=40-60° C.) was added and thecatalyst precipitated out of solution. The solution of the product wasdecanted and the flask washed with a further 15 cm³ of petroleum ether.The solvent was evaporated from the combined petroleum ether extractsand the product purified by vacuum distillation (bp=160-170° C. @ 1mmHg) in a Kugelrohr apparatus. This gave methylbenzophenone (4.05 g,97% isolated yield). The catalyst can be reused immediately by addingtoluene and benzoyl chloride to the flask (containing the precipitate)and repeating the reaction.

EXAMPLE 2 The reaction of Toluene with Benzoyl Chloride with Cobalt(II)bis-triflimide Catalyst in [emim] [NTf₂]

Cobalt(II) bis-triflimide (0.13 g, 0.21 mmol) was added to1-ethyl-3-methylimidazolium bis-trifluoromethanesulfonimide([emim][NTf₂]) (2.0 g) in a 25 cm³ round-bottomed flask equipped with amagnetic stirrer and reflux condenser, and the mixture stirred until thecatalyst dissolved. Toluene (3.0 g, 32.5 mmol) and benzoyl chloride (3.0g, 21.3 mmol) were added. The mixture was heated under reflux for 0.5hours (judged to be at least 99% complete by gas chromatographicanalysis), and cooled to room temperature. Petroleum ether (15 cm³,bp=40-60° C.) was added and the catalyst and ionic liquid formed aseparate phase. The solution of the product was decanted and the flask(containing the ionic liquid and catalyst) washed three times with 15cm³ of petroleum ether. The solvent was evaporated from the combinedpetroleum ether extracts and the product purified by vacuum distillation(bp=160-170° C. @ 1 mmHg) in a Kugelrohr apparatus. This gavemethylbenzophenone (4.02 g, 96%). The catalyst and ionic liquidcombination can be reused immediately by adding toluene and benzoylchloride to the flask and repeating the reaction, without loss ofactivity.

Examples 1 and 2 show that the acylation of toluene with benzoylchloride can be carried out with a cobalt(II) bis-triflimide catalystand that this can be performed with or without an ionic liquid present.However, with the ionic liquid, faster reaction rates are obtained andthe catalyst can be recycled more easily. Without the ionic liquid, theproducts of this reaction are obtained in quantitative yield using 1 mol% catalyst after 3 hours heating under reflux (example 1). The reactiontime is reduced to 30 minutes when the reaction is carried out in theionic liquid [emim][NTf₂] ([emim]=1-ethyl-3-methylimidazolium) (example2).

EXAMPLE 3 The Reaction of Toluene with Benzoyl Chloride with Nickel(II)bis-triflimide Catalyst in [emim] [NTf₂]

Nickel(II) bis-triflimide (0.13 g, 0.21 mmol) was added to1-ethyl-3-methylimidazolium bis-trifluoromethanesulfonimide ([emim][NTf₂]) (2.0 g) 25 cm³ in a round-bottomed flask equipped with amagnetic stirrer and reflux condenser, and the mixture stirred until thecatalyst dissolved. Toluene (3.0 g, 32.5 mmol) and benzoyl chloride (3.0g, 21.3 mmol) were added. The mixture was heated under reflux for 1 hour(judged to be at least 99% complete by gas chromatographic analysis),and cooled to room temperature. Petroleum ether (15 cm³, bp=40-60° C.)was added and the catalyst and ionic liquid formed a separate phase. Thesolution of the product was decanted and the flask (containing the ionicliquid and catalyst) washed three times with 15 cm³ of petroleum ether.The solvent was evaporated from the combined petroleum ether extractsand the product purified by vacuum distillation (bp=160-170° C. @ 1mmHg) in a Kugelrohr apparatus. This gave methylbenzophenone (4.04 g,97% isolated yield). The catalyst and ionic liquid combination can bereused immediately by adding toluene and benzoyl chloride to the flaskand repeating the reaction, without loss of activity.

The results from Examples 2 and 3 are shown in Table.

TABLE 1 The gas chromatographic (GC) yields of benzophenones derivedfrom the reaction of benzoyl chloride with toluene with 1% metalbis-triflimide catalyst in [emim][NTf₂]. Compound Yield Time/h Co(NTf₂)₂99 0.5 Ni(NTf₂)₂ 99 1

EXAMPLE 4

Anisole (0.30 cm³, 2.8 mmol), acetic anhydride (0.50 cm³, 5.0 mmol),M(NTf₂)_(n) catalyst (0.1375 mmol (M=Al, n=3; M=Zn, n=2; M=Yb, n=3; M=Y,n=3)) were dissolved in the ionic liquid [bmim] [PF₆]. These fourreactions were heated at 30° C. for 24 hours. The course of the reactionwas determined by HPLC analysis of the reaction mixture and the yieldsare shown in Table 2.

TABLE 2 The variation of GC yield with time for the acetylation ofanisole with acetic anhydride with metal bis-triflimide catalysts in[bmim][PF₆]. % Yield % Yield % % Catalyst (35 min) (115 min) Yield (245min) Yield (1375 min) Al(NTf₂)₃ 45 55 61 63 Zn(NTf₂)₃ 23 36 44 61Yb(NTf₂)₃ 49 61 64 69 Y(NTf₂)₃ 55 62 71

EXAMPLE 5

Anisole (0.50 cm³, 4.6 mmol), benzoic anhydride (1.15 g, 5.06 mmol),M(NTf₂)_(n) catalyst (0.23 mmol (M=Al, n=3, 0.20 g; M=Ce, n=4, 0.29 g))were dissolved in the ionic liquid [bmim] [NTf₂] (2.0 g). These tworeactions were heated at 60° C. for 24 hours. The course of the reactionwas determined by gas chromatographic analysis of the reaction mixtureand the yields are shown in Table 3.

TABLE 3 The variation of GC yield with time for the benzoylation ofanisole with benzoic anhydride with metal bis-triflimide catalysts in[bmim][PF₆]. % Yield % Yield % % Catalyst (60 min) (120 min) Yield (180min) Yield (1350 min) Al(NTf₂)₃ 44 62 67 68 Ce(NTf₂)₄ 32 49 56 84

EXAMPLE 6

Fluorobenzene (5.77 g, 60 mmol), 4-fluorobenzoyl chloride (4.75 g, 30mmol), ZnCl₂ (1.36 g, 10 mmol) and [emim] [NTf₂] were placed in anautoclave and heated with stirring for 48 hours at 160° C. The reactorwas cooled and the pressure (HCl gas) released. Gas chromatographicanalysis showed that a 99% conversion to a mixture of2,4′-difluorobenzophenone, 3,4′-difluorobenzophenone,4,4′-difluorobenzophenone in 17:8:75 ratio respectively. Thedifluorobenzophenones were isolated by solvent extraction with petroleumether (bp=40-60° C.), followed by evaporation of the solvent. The ionicliquid/zinc chloride catalyst system could be used in further reactions,with similar activity. This result shows that the classically unreactivearomatic compound fluorobenzene can be acylated with 4-fluorobenzoylchloride to give isomers of 2-, 3-, or 4-4′-difluorobenzophenone in[emim] [NTf₂] using an in situ zinc catalyst. This catalyst wasgenerated by dissolving zinc(II) chloride in the [emim] [NTf₂] ionicliquid. The reaction gave a 95% yield (17:8:75 o-, m-, p-isomer ratio).

EXAMPLE 7

Benzoic acid (0.31 g, 2.5 mmol), m-xylene (0.53 g, 5.0 mmol), [bmim][NTf₂] (0.50 g) and M(NTf₂)₂ (M=Co (0.14 g, 0.25 mmol), or Zn (0.15 g,0.25 mmol) were placed in flasks equipped with stirrers and condensers.The contents of the flask were heated under reflux (ca 140-150° C.) for2 days, then cooled to room temperature. The products were analysed bygas chromatographic analysis and found to give 93 and 87% conversions(for Co and Zn bis-triflimide reactions respectively) to2,4-dimethylbenzophenone and, it is believed to be,2,6-dimethylbenzophenone (11:1 isomer ratio in both cases). The resultsshow that Zinc and cobalt bis-triflimide have been found to catalyse thebenzoylation of m-xylene with benzoic acid. The reaction is slower thatthe corresponding reaction with benzoyl chloride. The catalyst wasrecycled and the reaction was repeated. The results of the repeatexperiment are shown in Table 4.

TABLE 4 The yields of benzophenones derived from the reaction of benzoicacid with m-xylene with 10% recycled metal bis-triflimide catalyst in[bmim][NTf₂] at 140° C. for 48 hours. Compound % Yield 2,4- to 2,6-ratio Zn(NTf₂)₂ 40 11:1 Co(NTf₂)₂ 82 11:1

These are remarkable results given the low reactivity of benzoic acid.It is to be noted that this reaction produces water as a byproduct andas such it is a very environmentally friendly reaction. Furthermore, itutilises a non corrosive starting material (benzoic acid) and thereforeis an safer reaction to perform than the corresponding reaction withbenzoyl chloride. It can be concluded that this is a superior way toproduce dimethylbenzophenone.

EXAMPLE 8 The Reaction of Toluene with Benzoyl Chloride with Zinc(II) orCopper(II) bis-triflimide Catalyst in [emim][NTf₂]

Copper or zinc (II) bis-triflimide (0.13 g, 0.21 mmol) was added to amixture of toluene (3.0 g, 32.5 mmol) and benzoyl chloride (3.0 g, 21.3mmol). The mixture was heated under reflux for 72 hours (the reactionwas monitored by gas chromatographic analysis, by taking a drop of thereaction mixture and suspending it in petroleum ether (b.p.=40-60° C.)and filtering off the catalyst. The starting materials and products,which are soluble in the petroleum ether extract, were cooled to roomtemperature. Petroleum ether (15 cm³, bp=40-60° C.) was added and thecatalyst and formed a separate phase. The solution of the product wasdecanted and the flask (containing the catalyst) washed three times with15 cm³ of petroleum ether. The solvent was evaporated from the combinedpetroleum ether extracts and the product purified by vacuum distillation(bp=160-170° C. @ 1 mmHg) in a Kugelrohr apparatus. This gavemethylbenzophenone (4.0 g, 95%). The catalyst can be reused immediatelyby adding toluene and benzoyl chloride to the flask and repeating thereaction, without loss of activity. The yields as determined by gaschromatographic analysis are shown in Table 5.

TABLE 5 the yields of benzophenones derived from the reaction of benzoylchloride with toluene with 1% copper(II) or 1% zinc(II) bis-triflimidecatalysts. The figure in brackets refers to the o-, m- and p- isomerratios. Yield with Yield with Time/h Zn(NTf₂)₂ Cu(NTf₂)₂ 24 83 52 48 99(22:1:77) 72 99 (20:2:78)

Zinc(II) and copper(II) bis-triflimide compounds were found to beeffective acylation catalysts for the benzoylation of toluene.

EXAMPLE 9 The Reaction of o-xylene with Benzoyl Chloride with anAluminium(III) bis-triflimide Catalyst

Aluminium (III) bis-triflimide (0.10 g) was added to a mixture ofo-xylene (3.0 g, 28.2 mmol) and benzoyl chloride (3.0 g, 21.3 mmol). Themixture was heated at 120° C. for 18 hours (the reaction was monitoredby gas chromatographic analysis, by taking a drop of the reactionmixture and suspending it in petroleum ether (b.p.=40-60° C.) andfiltering off the catalyst. The starting materials and product aresoluble in the petroleum ether extract), and cooled to room temperature.Petroleum ether (15 cm³) was added and the catalyst and formed aseparate phase.

The yields as determined by gas chromatographic analysis was 99% with a6.0:1 3,4- to 2,3-dimethylbenzophenone isomer ratio. Aluminium(III)bis-triflimide was found to be an effective catalyst for thebenzoylation of o-xylene. The reaction gave a quantitative yield of twoisomers of the corresponding benzophenone (6:1 3,4- to 2,3-isomer ratio)after 18 h at 120° C., using 1 mol % of catalyst.

EXAMPLE 10 The Reaction of Toluene with Benzoyl Chloride with Metalbis-triflimide Catalyst

Various metal (1-ethyl-3-methylimidazolium, Li, Mg, Ca, Mn, Co, Ni, Cu,Zn, Sn, Pb, Al) bis-triflimide salts (1 mol %) was added to a mixture oftoluene (3.0 g, 32.6 mmol) and benzoyl chloride (3.0 g, 21.3 mmol). Themixture was heated at 110° C. for up to 120 hours. The reaction wasmonitored at regular intervals by gas chromatographic analysis and thereaction stopped when the reaction was judged to be 99% complete bycooling to room temperature. Petroleum ether (15 cm³) was added and thecatalyst and formed a separate phase. The product was isolated bedecanting the petroleum ether extract, followed by Kugenrohrdistillation at 1 mm Hg. The yields after various time intervals aregiven in Table 6. The product formed is methylbenzophenone. In all thesereactions, the isomer ratio was found to be approximately 76% para and24% ortho. This results are shown in Table 6. Table 1 lists the timesrequired for Co and Ni bis-triflimide in [emim] [NTf₂].

TABLE 6 The yields of benzophenones derived from the reaction of benzoylchloride with toluene with 1% metal bis-triflimide catalyst. CompoundYield/% Time/h [emim][NTf₂] <1 48 Li NTf₂ <5 120 Mg(NTf₂)₂ 99 48Ca(NTf₂)₂ <5 120 Mn(NTf₂)₂ 99 5 Co(NTf₂)₂ 99 3 Ni(NTf₂)₂ 99 4 Cu(NTf₂)₂99 72 Zn(NTf₂)₂ 99 48 Sn(NTf₂)₂ 55 48 Pb(NTf₂)₂ 95 6 Al(NTf₂)₃ 99 24

From Table 6, a remarkable difference in reactivity between thecompounds chosen is observed. Of these, four compounds appear to haveunexpectedly high reactivity, namely those of manganese, cobalt, nickeland lead, whereas compounds such as zinc bis-triflimide and aluminiumbis-triflimide have relatively modest activity. This is completelydifferent to “conventional Friedel-Crafts chemistry” which would suggestthat the Al bistriflimide should be the best catalyst. Of particularremark is the catalytic reactivity of Co and Pb. Lithium and calciumbis-triflimide in contrast show very poor activity and with [emim][bis-triflimide], little or no reaction was observed.

EXAMPLE 11 The Reaction of Chlorobenzene with Benzoyl Chloride withNickel(II) bis-triflimide Catalyst in [bmim] [NTf₂]

Nickel(II) bis-triflimide (0.062 g, 0.1 mmol) was added to1-butyl-3-methylimidazolium bis-trifluoromethanesulfonimide ([bmim][NTf₂]) (1.0 g) in a 25 cm³ round-bottomed flask equipped with amagnetic stirrer and reflux condenser, and the mixture stirred until thecatalyst dissolved. Chlorobenzene (1.68 g, 15 mmol) and benzoyl chloride(1.41 g, 10 mmol) were added. The mixture was heated under reflux for 72hours and was analysed by gas chromatographic analysis as in previousexamples. The reaction was cooled to room temperature. Petroleum ether(15 cm³, bp=40-60° C.) was added and the catalyst and ionic liquidformed a separate phase from the petroleum ether layer. The solution ofthe product (in petroleum ether) was decanted and the flask (containingthe ionic liquid and catalyst) washed three times with 15 cm³ ofpetroleum ether. Concentration of the organic extract, followed byKugenrohr distillation at 1 mm Hg (bp=170-190° C.), gavechlorobenzophenone (1.65 g, 74%) GC analysis showed 78% yield after 72hours, with a 70:8 4- to 2-isomer ratio. This is a remarkable result, aschlorobenzene is known to be classically unreactive in acylationreactions. It has not previously been possible to isolate significantquantities of the products of the acylation of chlorobenzene.

EXAMPLE 12 The Reaction of Chlorobenzene with Benzoyl Chloride withCobalt(II) bis-triflimide or Zinc(II) bis-triflimide Catalyst in [bmim][NTf₂]

In two separate reactions, either zinc(II) bis-triflimide (0.16 g, 5 mol%) or cobalt(II) bis-triflimide (0.15 g, 5 mol %) was added to1-butyl-3-methylimidazolium bis-trifluoromethanesulfonimide ([bmim][NTf₂]) (1.0 g) 25 cm³ in a round-bottomed flask equipped with amagnetic stirrer and reflux condenser, and the mixture was heated gentlyand stirred until the catalyst dissolved. Chlorobenzene (0.68 g, 6 mmol)and benzoyl chloride (0.72 g, 5 mmol) were added. The mixture was heatedunder reflux for 18 hours and was analysed by gas chromatographicanalysis as in previous examples. The reaction was cooled to roomtemperature. Cyclohexane (15 cm³) was added and the catalyst and ionicliquid formed a separate phase. The solution of the product was decantedand the flask (containing the ionic liquid and catalyst) washed threetimes with 15 cm³ cyclohexane followed by Kugelrohr distillation at 1 mmHg (bp=180-200° C.) This gave a mixture of 2- and 4-chlorobenzophenone.GC yield=97% (6.8:1 p- to o-isomer ratio) for cobalt catalyst and 55% GCyield (6.5:1 p- to o-isomer ratio) for the zinc catalyst.

The reaction of chlorobenzene with benzoyl chloride was investigated, aschlorobenzene is much more difficult to acylate. Although reasonableyields could be obtained with 1 mol % catalyst, it was found that 5-mol% catalyst gave more acceptable reaction rates. The reaction was foundto be 95% complete with cobalt bis-triflimide after 18 hours and 55%complete with zinc bis-triflimide (Table 7). The catalyst was found tobe less active after extracting the product with boiling cyclohexane andrecycling the ionic liquid/catalyst. The activity of the catalyst wasrestored by adding a trace of hydrogen bis-triflimide (0.1 mol %).

TABLE 7 The yields of benzophenones derived from the reaction of benzoylchloride with chlorobenzene with 5% metal bis-triflimide catalyst in[bmim][NTf₂]. Compound Yield Time/h Co(NTf₂)₂ 95 18 Zn(NTf₂)₂ 55 18

EXAMPLE 13 The Reaction of Toluene with Benzoyl Chloride with Hydrogenand Metal bis-triflimide Catalyst

Various metal bis-triflimide compounds: Sr(II), Ba(II), In(III), In(III)in [bmim] [NTf₂], Cr(III), Ce(IV), Yb(III), and hydrogen bis-triflimide{HN(SO₂CF₃)₂} (1 mol %) were added to a mixture of toluene (1.38 g, 15.0mmol) and benzoyl chloride (1.41 g, 10.0 mmol). The mixture was heatedat 110° C. for up to 120 hours. The reaction was monitored at variousintervals by gas chromatographic analysis and the reaction stopped after5 days. The yields of methylbenzophenone with respect to time are shownin FIG. 1. The reaction of benzoyl chloride and toluene gave 2- and4-methylbenzophenone. All these compounds were found to be activeFriedel-Crafts catalysts, but with considerably different activities. Ofthese, the activities of indium(III) and iron(III) (Example 14) are themost notable, as they are exceptionally good catalysts. The p- too-selectivities were in the range 3.9 to 4.4 to 1, with the indium andiron catalysts giving 4.4:1 selectivity.

EXAMPLE 14 The Reaction of Toluene with Benzoyl Chloride with Iron(III)bis-triflimide or Iron(III) Chloride Dissolved in [bmim] [NTf₂]

In two separate reactions, either iron(III) bis-triflimide (1 mol %) oriron(III) chloride (1 mol %) was added to 1-butyl-3-methylimidazoliumbis-trifluoromethanesulfonimide ([bmim] [NTf₂]) (1.0 g) 25 cm³ in around-bottomed flask equipped with a magnetic stirrer and refluxcondenser, and the mixture was heated gently and stirred until thecatalyst dissolved. Toluene (1.38 g, 15 mmol) and benzoyl chloride (1.41g, 10 mmol) were added. The mixture was heated under reflux for 48 hoursand was analysed by gas chromatographic analysis as in previousexamples. The yield of methylbenzophenone with respect to time is shownin FIG. 2. Here, the activity of the iron catalyst was tested in twoseparate ways: (a) with 1% FeO(NTf₂) in [bmim] [NTf₂] and (b) 1% FeCl₃in [bmim] [NTf₂]. In both cases, the activity and selectivity weresimilar, indicating that FeCl₃ and FeO(NTf₂) are possibly precursors tocatalyst, when dissolved in excess [bmim] [NTf₂].

EXAMPLE 15 The Reaction of Toluene with Methane Sulfonyl Chloride withZinc(II) bis-triflimide

Zinc(II) bis-triflimide (0.13 g, 2.5 mol %) was added to around-bottomed flask equipped with a magnetic stirrer and refluxcondenser. Toluene (1.38 g, 15 mmol) and methane sulfonyl chloride (1.14g, 10 mmol) were added. The mixture was heated under reflux for 24 hoursand was analysed by gas chromatographic analysis as in previousexamples. All the methane sulfonyl chloride had reacted and threeisomers of (2-, 3- and 4-methylphenyl)methylsulfone had formed(yield=99%), isomer ratio=35:18:47 for the o-, m- and p-isomers. Theproduct was extracted from the catalyst by dissolving it in cyclohexane(20 cm³) followed by decantation of the cyclohexane extract. Thecatalyst was washed with cyclohexane (2×20 cm³) and the combinedcyclohexane extracts were concentrated on a rotary evaporator. Theproduct was Kugelrohr distilled at 100-110° C. to give 1.62 g of acolourless oil (96% isolated yield).

EXAMPLE 16 The Reaction of Benzene with Benzene Sulfonyl Chloride withZinc(II) bis-triflimide

Zinc(II) bis-triflimide (0.062 g, 1 mol %) was dissolved in [bmim][NTf₂] (1.0 g) in a round-bottomed flask equipped with a magneticstirrer and reflux condenser. Benzene (1.56 g, 20 mmol) and benzenesulfonyl chloride (1.76 g, 10 mmol) were added. The mixture was heatedunder reflux for 18 hours and was analysed by gas chromatographicanalysis as in previous examples. All the benzene sulfonyl chloride hadreacted diphenyl sulfone had formed (yield=99%). The product wasextracted from the catalyst and ionic liquid by dissolving it in boilingcyclohexane (5×30 cm³) followed by decantation of the cyclohexaneextract. The diphenylsulfone crystalised on cooling and was collected byfiltration (2.03 g, 93% isolated yield). The reaction of benzene withbenzene sulfonyl chloride gave the expected diphenyl sulfone in 99%yield with a Zn(NTf₂)₂ catalyst (18 h at reflux) The diphenyl sulfonewas extracted with boiling cyclohexane and the ionic liquid and catalystcould be reused.

EXAMPLE 17 The Reaction of m-xylene with Benzene Sulfonyl Chloride withZinc(II) bis-triflimide

Zinc(II) bis-triflimide (0.062 g, 1 mol %) was dissolved in [bmim][NTf₂] (1.0 g) in a round-bottomed flask equipped with a magneticstirrer and reflux condenser and m-xylene (2.12 g, 20 mmol) and benzenesulfonyl chloride (1.76 g, 10 mmol) were added. The mixture was heatedunder reflux for 18 hours and was analysed by gas chromatographicanalysis as in previous examples. All the benzene sulfonyl chloride hadreacted and mostly 2,4-dimethyldiphenylsulfone had formed (yield=99%,20:1 isomer ratio {by NMR}). The major product is shown below, thestructure of the minor isomer is not known but is believed to be the2,6-dimethyl isomer.

The product was extracted from the catalyst and ionic liquid bydissolving it in boiling cyclohexane (5×30 cm³) followed by decantationof the cyclohexane extract. The 2,4-dimethyldiphenylsulfone crystalisedon cooling and was collected by filtration.

EXAMPLE 18 The Reaction of Chlorobenzene with Benzene Sulfonyl Chloridewith Metal bis-triflimide Catalysts

In three separate reactions, either magnesium(II) bis-triflimide (0.058g, 0.1 mol), aluminium(III) bis-triflimide (0.87 g, 0.1 mmol) orcobalt(II) bis-triflimide (0.062 g, 0.1 mmol) was dissolved in [bmim][NTf₂] (0.5 g) in a round-bottomed flask equipped with a magneticstirrer and reflux condenser. Chlorobenzene (1.68 g, 15 mmol) andbenzene sulfonyl chloride (1.76 g, 10 mmol) were added. The mixture washeated under reflux for 144 hours and monitored by gas chromatographicanalysis as in previous examples. The yields with respect to time aregiven in FIG. 3. The product was extracted from the catalyst and ionicliquid by dissolving it in boiling cyclohexane (4×10 cm³) followed bydecantation of the cyclohexane extract. The 2- and4-chlorodiphenylsulfone (9:1 p- to o-isomer ratio) crystalised oncooling and was collected by filtration. The selectivity was 9:1 for thep-isomer and the o-isomer was the minor isomer in all cases.Coincidently, the reaction of benzoyl chloride with chlorobenzene alsogave the same selectivity and similar reaction rates.Phenyl-4-chlorophenylsulfone is an insecticide. The reaction was foundto be slow using 1 mol % catalyst, but 5 mol % catalyst gave acceptablereaction rates. The metal salts chosen were aluminium(III), cobalt(II)and magnesium(II) bis-triflimide, in the ionic liquid [bmim] [NTf₂]. Allthree catalysts were found to be effective for this reaction. Thereaction is shown below.

EXAMPLE 19 The Reaction of Benzene with oct-1-ene with Nickel(II)bis-triflimide

Nickel(II) bis-triflimide (0.06 g, 0.1 mmol) was dissolved in [bmim][NTf₂] (1.0 g) in a round-bottomed flask equipped with a magneticstirrer and reflux condenser. Benzene (3.90 g, 50 mmol) and oct-1-ene(1.12 g, 10 mmol) were added. The mixture was heated under reflux for 18hours and was analysed by gas chromatographic analysis as in previousexamples. The oct-1-ene peak disappeared and three isomers ofoctylbenzene were formed (70%, 20:26:54 2- to 3- to 4-isomer ratio) aswell as octene dimer (30%). The less dense product phase was decantedfrom the ionic/catalyst phase and purified by Kugelrohr distillation.The ionic liquid and catalyst were prepared for reuse by heating at 60°C. under vacuum for 1 hour. The ionic liquid and catalyst were used forfurther reactions of benzene with oct-1-ene without loss of activity.This is an alkylation of benzene with an alkene using a metalbis-triflimide catalyst. Benzene and oct-1-ene react in the presence of1% nickel(II) bis-triflimide in [bmim] [NTf₂] to form three isomers ofoctyl benzene and a small amount of hexadecene (unknown isomericdistribution). This reaction shown below:

The alkylation of benzene with oct-1-ene. The reaction gave a 70% yield(by GC) of three isomers of octylbenzene. The isomer ratio wasdetermined to be 0.75:1.00:2.03, with the 4-phenyloctene as the majorproduct and 2-phenyloctene as the minor product. During the course ofthe reaction, isomeration of oct-1-ene to a number of isomers of octenewas observed, and the rate of this isomerisation process wasconsiderably faster that the alkylation reaction. It was found that theionic liquid/catalyst combination remained active on a second run. Toconfirm that the minor product of the reaction was an octene dimer, thesame reaction was performed, but without any benzene present (shownbelow).

The dimerisation of oct-1-ene.

The reaction proceeded initially with isomerisation of octene to amixture of 4 isomers of octene. After 18 hours, the reaction was almostcomplete (>95% conversion). The products were a large number of isomersof dimerised and trimerised octene. As the reaction was left to run for6 days, a broadening of the cluster of GC peaked for the dimer andtrimer was observed, indicating that further isomerisation wasoccurring.

EXAMPLE 20 The Dimerisation of oct-1-ene with Nickel(II) bis-triflimide

Nickel(II) bis-triflimide (0.062 g, 0.1 mmol) was dissolved in [bmim][NTf₂] (0.5 g) in a round-bottomed flask equipped with a magneticstirrer and reflux condenser. Oct-1-ene (1.12 g, 10 mmol) was added. Themixture was heated under reflux for 18 hours and was analysed by gaschromatographic analysis as in previous examples. The oct-1-ene peakdisappeared and three isomers of octene (oct-2-ene, oct-3-ene andoct-4-ene) were formed. Hydrogen bis-triflimide was added (0.0028 g, 0.1mmol) and the mixture was heated for a further 18 hours. Gaschromatographic analysis showed that the reaction was almost complete(>99%), and gave a mixture of isomers of hexadecene and tetracosene(trimer of octene). The less dense product phase was decanted from theionic/catalyst phase and purified by Kugelrohr distillation at 1 mm Hg.The ionic liquid and catalyst were prepared for reuse by heating at 60°C. under vacuum for 1 hour. The ionic liquid and catalyst were used forfurther dimerisation reactions of oct-1-ene without loss of activity.

EXAMPLE 21 The Fries Rearrangement of 4-methylphenoxybenzoate withHydrogen and Metal bis-triflimide Compounds

Ytterbium(III) bis-triflimide (0.1 g) and hydrogen bis-triflimide (0.01g) was dissolved in [n-H₂₉C₁₄(n-H₁₃C₆)₃ P] [NTf₂] (1.0 g) in around-bottomed flask equipped with a magnetic stirrer and refluxcondenser. 4-methylphenoxybenzoate (1.0 g) was added. The mixture washeated under reflux for 24 hours at 60° C. and was analysed by gaschromatographic analysis as in previous examples. The product of thereaction was 2-hydroxy-5-methylbenzophenone (90% yield). Theisomerisation of 4-methylphenoxybenzoate to2-hydroxy-5-methylbenzophenone is shown below.

EXAMPLE 22 The Reaction of o-xylene, m-xylene, Mesitylene, and Toluenewith Cyclohexene with Metal bis-triflimide Compounds

In four separate reaction vessels, ytterbium(III) bis-triflimide (0.1 g)was dissolved in [n-H₂₉C₁₄(n-H₁₃C₆)₃P] [NTf₂] (2.0 g) in around-bottomed flask equipped with a magnetic stirrer and refluxcondenser. Either o-xylene (1.06 g, 10 mmol), m-xylene (1.06 g, 10mmol), mesitylene (1.20 g, 10 mmol), or toluene (0.92 g, 10 mmol) wereadded to the separate flasks followed by addition of cyclohexene (0.82g, 10 mmol). The mixtures were heated at 80° C. for 12 hours and wereanalysed by gas chromatographic analysis as in previous examples. Thecyclohexene peak disappeared and peak(s) due to alkylation of thearomatic compound and peaks due to dimerisation reactions of cyclohexenewere formed (see Example 26 for details). The ionic liquid and catalystwere prepared for reuse by heating at 60° C. under vacuum for 1 hour.The ionic liquid and catalyst were used for further reactions of benzenewith cyclohexene without loss of activity.

EXAMPLE 23 The Reaction of Benzene with dodec-1-ene with Metalbis-triflimides, Triflates and Hydrogen bis-triflimide

In ten separate reaction vessels (a multi-cell glass reactor withstirrers and condensers) metal triflimide or metal triflate compounds(see Table below) were added together with hydrogen bis-triflimide (0.01g) to [n-H₂₉C₁₄(n-H₁₃C₆)₃P] [NTf₂] (2.0 g) and stirred until the metalcompound had dissolved. Benzene (3.8 g, 50 mmol) and dodec-1-ene (0.84g, 5.0 mmol) were added. The mixtures were heated at 80° C. for 24hours. The excess benzene was distilled off. The mixture was analysed byNMR upon cooling to room temperature. The ionic liquid and catalyst wereprepared for reuse by heating at 60° C. under vacuum for 1 hour. Theionic liquid and catalyst were used for further reactions of benzenewith dodec-1-ene without loss of activity. The results are shown inTable 8 below.

TABLE 8 Unreacted Isomerised Dodecyl Compound Mass/g dodecene dodecenebenzene Yb(NTf₂)₃ 1.02 0 0 100 Co(NTf₂)₂ 0.62 0 99 1 Cu(NTf₂)₂ 0.62 0 199 Pb(NTf₂)₂ 0.76 0 100 0 In(NTf₂)₃ 0.95 0 0 100 Ga(NTf₂)₃ 0.63 0 61 39Zn(OTf₂)₂ 0.36 67 33 0 Cu(OTf₂)₂ 0.36 1 96 3 Yb(OTf₂)₃ 0.53 0 91 9La(OTf₂)₃ 0.59 0 60 40

EXAMPLE 24 The Reaction of Toluene with Benzoyl Chloride with MetalCompounds Dissolved in [bmim] [NTf₂]

In five separate reactions, either titanium(IV) chloride (1 mol %) ortin(IV) chloride (1 mol %), or tungsten(VI) chloride, or hafnium(IV)chloride or palladium(II) chloride was added to1-butyl-3-methylimidazolium bis-trifluoromethanesulfonimide ([bmim][NTf₂]) (2.0 g) 25 cm³ in a round-bottomed flask equipped with amagnetic stirrer and reflux condenser, and the toluene (2.81 g, 30 mmol)and benzoyl chloride (2.84 g, 20 mmol) were added. The mixtures washeated under reflux for 24 hours and was analysed by gas chromatographicanalysis as in previous examples. The conversion of starting materialsto methylbenzophenone was quantitative except for the palladium(II)catalysed reaction (75% yield). The variation of yield with time in thereaction of several new metal bis-triflimide salts in the reaction ofbenzoyl chloride with toluene in given in FIG. 4. These reactions wereperformed in parallel, and the yields were determined by GC analysis.

In this invention, the use of a metal halide dissolved in abis-triflimide ionic liquid can be used for reactions such as theFriedel-Crafts reactions. This is useful where a particular metalbis-triflimide salt is difficult to prepare or isolate. In thisinvention, five metal halides (chlorides) (1 mol % with respect to thereactants) were dissolved in [bmim] [NTf₂]. This combination was used tocatalyse the reaction of toluene with benzoyl chloride to givemethylbenzophenone. The yield with respect to time is given in FIG. 4.All of the metals chosen gave the expected products in good yield, butthe combination of 1% mol tin(IV) chloride in [bmim] [NTf₂] was aparticularly effective catalyst. This process of using metal compoundsdissolved in an ionic liquid (usually bis-triflimide) can also be usedwith compounds of other metals (particularly transition metals (d-block)or f-block metals)) not listed in FIG. 3 or 4.

EXAMPLE 25

A number of aromatic sulfonylation reactions were performed. Thesereactions are very similar to Friedel-Crafts acylation reactions and areperformed under similar conditions. The key difference is that a —SO₂—Xgroup replaces a —CO—X (X=leaving group). In most cases, theselectivities, reactivities and yields were found similar to thecorresponding acylation reaction. The reaction of sulfuryl chloride withbenzene resulted in the formation of chlorobenzene (quantitatively) andSO₂. This is as is found in many other reactions of SO₂Cl₂ with aromaticcompounds performed in molecular solvents.

EXAMPLE 26

The alkylation of various aromatic compounds with cyclohexene in aphosphonium ionic liquid with 10% ytterbium(III) bis-triflimide with atrace of hydrogen bis-triflimide were carried out. A side reaction alsotakes place that results in the formation of a dimer of cyclohexene (seebelow) and this results in a slight reduction in the yield of theFriedel-Crafts reaction. However, is should be noted that thisdemonstrates that metal triflimide compounds can be used fordimerisation and oligomerisation reactions.

The reaction of aromatics with cyclohexene in a phosphonium ionic liquidfor 12 hours at 80° C. is shown above. Below is shown the dimerisationof cyclohexene.

1. A process for carrying out a chemical reaction which is catalysed byone or more metal fluoroalkylsulfonylated compound, which processcomprises carrying out said reaction in the presence of an ionic liquidor in solvent-free conditions, and characterized in that thefluoroalkylsulfonylated compound is generated in situ.
 2. A processaccording to claim 1 wherein the one or more metalfluoroalkylsulfonylated compound is a metal bistriflimide compound.
 3. Aprocess according to claim 2 wherein the bistriflimide compound has thefollowing formula:M_(x) ^(n+)[{N(SO₂CF₃)₂}]_((nx-yz)) ^((nx-yz)−)L_(y) ^(z−) Where M is ametal; L is a negative or neutral ligand N is 2, 3, 4, 5, 6, 7or 8 X isgreater than or equal to 1; Y is 0, 1, 2, 3, 4, 5, 6, 7 or 8; and Z is0, 1, 2, 3 or
 4. 4. A process according to claim 3 wherein M is a metalselected from the metals in groups 1 to 16 and the lanthanides and theactinides.
 5. A process according to claim 1 wherein the chemicalreaction is one of: (a) an electrophillic substitution reaction, or (b)an isomerisation, polymerization or rearrangement of a chemical compoundor molecule.
 6. A process according to claim 5 wherein the chemicalreaction is a reaction between an aromatic compound and an alkylating,acylating or sulfonating agent.
 7. A process according to claim 5wherein the chemical reaction is a rearrangement of esters of phenols toacyl phenols.
 8. A process according to claim 1 wherein carrying outsaid reaction in solvent free conditions the comprises adding one ormore hydrogen fluoroalkylsulfonylated compound directly to the reaction.9. A process according to claim 1 wherein carrying out the reaction inthe presence of an ionic liquid which comprises dissolving or suspendingone or more hydrogen fluoroalkylsulfonylated compound in an ionicliquid.
 10. A process according to claim 9 wherein the ionic liquidcomprises a cation chosen from 1-alkylpyridinium or1,3-dialkylimidazolium cation, alkyl- or poly-alkylpyridinium, alkyl orpoly-alkylimidazolium, alkyl or poly-alkylpyrazolium, alkyl orpoly-alkyl ammonium, alkyl or poly-alkyl phosphonium, and alkylateddiazabicyclo-[5,4,0]-undec-7-ene; and an anion chosen frombis-trifluoromethanesulfonimide, bis-pentafluoroethanesulfonimide,hexafluorophosphate (V), tetrafluoroborate (III),trifluoromethanesulfonate, cyanamide, fluoro or perfluoroalkylsulfonate,halide, sulfate, hydrogensulfate, alkylsulfate, alkylsulfonate,arylsulfate, arylsulfonate, nitrate, carboxylate, phosphate,hydrogenphosphate, dihydrogenphosphate, alkylphosphate,alkylphosphonate, phosphonate, nitrite, arsenate, antimonate,haloaluminate, aluminate, borate, silicate, haloindate (III), gallate,alkylborate and halogallate.
 11. A process according to claim 1 whereinthe catalyst or the catalyst and ionic liquid combination aresubsequently separated from the reaction mixture.
 12. A processaccording to claim 11 wherein the catalyst or the catalyst and ionicliquid combination are subsequently recycled.
 13. A process according toclaim 2 wherein M is a metal selected from the metals in group 1 to 16and the lanthanides and the actinides.
 14. A process according to claim3 wherein M is a metal selected from the metals in groups 1 to 16 andthe lanthanides and the actinides.
 15. A process according to claim 2wherein the chemical reaction is one of: (a) an electrophillicsubstitution reaction, or (b) an isomerisation, polymerization orrearrangement of a chemical compound or molecule.
 16. A processaccording to claim 3 wherein the chemical reaction is one of: (a) anelectrophillic substitution reaction, or (b) an isomerisation,polymerization or rearrangement of a chemical compound or molecule. 17.A process according to claim 4 wherein the chemical reaction is one of:(a) an electrophillic substitution reaction, or (b) an isomerisation,polymerization or rearrangement of a chemical compound or molecule. 18.A process according to claim 2 wherein carrying out said reaction insolvent free conditions comprises adding one or more hydrogenfluoroalkylsulfonylated compound directly to the reaction.
 19. A processaccording to claim 3 wherein carrying out said reaction in solvent freeconditions comprises adding one or more hydrogen fluoroalkylsulfonylatedcompound directly to the reaction.
 20. A process according to claim 4wherein carrying out said reaction in solvent free conditions comprisesadding one or more hydrogen fluoroalkylsulfonylated compound directly tothe reaction.
 21. A process according to claim 5 wherein carrying outsaid reaction in solvent free conditions comprises adding one or morehydrogen fluoroalkylsulfonylated compound directly to the reaction. 22.A process according to claim 6 wherein carrying out said reaction insolvent free conditions comprises adding one or more hydrogenfluoroalkylsulfonylated compound directly to the reaction.
 23. A processaccording to claim 7 wherein carrying out said reaction in solvent freeconditions comprises adding one or more hydrogen fluoroalkylsulfonylatedcompound directly to the reaction.
 24. A process according to claim 2wherein carrying out the reaction in the presence of an ionic liquidcomprises dissolving or suspending one or more hydrogenfluoroalkylsulfonylated compound in an ionic liquid.
 25. A processaccording to claim 3 wherein carrying out the reaction in the presenceof an ionic liquid comprises dissolving or suspending one or morehydrogen fluoroalkylsulfonylated compound in an ionic liquid.
 26. Aprocess according to claim 4 wherein carrying out the reaction in thepresence of an ionic liquid comprises dissolving or suspending one ormore hydrogen fluoroalkylsulfonylated compound in an ionic liquid.
 27. Aprocess according to claim 5 wherein carrying out the reaction in thepresence of an ionic liquid comprises dissolving or suspending one ormore hydrogen fluoroalkylsulfonylated compound in an ionic liquid.
 28. Aprocess according to claim 6 wherein carrying out the reaction in thepresence of an ionic liquid comprises dissolving or suspending one ormore hydrogen fluoroalkylsulfonylated compound in an ionic liquid.
 29. Aprocess according to claim 7 wherein carrying out the reaction in thepresence of an ionic liquid comprises dissolving or suspending one ormore hydrogen fluoroalkylsulfonylated compound in an ionic liquid.
 30. Aprocess according to claim 2 wherein the catalyst or the catalyst andionic liquid combination are subsequently separated from the reactionmixture.
 31. A process according to claim 3 wherein the catalyst or thecatalyst and ionic liquid combination are subsequently separated fromthe reaction mixture.
 32. A process according to claim 4 wherein thecatalyst or the catalyst and ionic liquid combination are subsequentlyseparated from the reaction mixture.
 33. A process according to claim 5wherein the catalyst or the catalyst and ionic liquid combination aresubsequently separated from the reaction mixture.
 34. A processaccording to claim 6 wherein the catalyst or the catalyst and ionicliquid combination are subsequently separated from the reaction mixture.35. A process according to claim 7 wherein the catalyst or the catalystand ionic liquid combination are subsequently separated from thereaction mixture.
 36. A process according to claim 8 wherein thecatalyst or the catalyst and ionic liquid combination are subsequentlyseparated from the reaction mixture.
 37. A process according to claim 9wherein the catalyst or the catalyst and ionic liquid combination aresubsequently separated from the reaction mixture.
 38. A processaccording to claim 10 wherein the catalyst or the catalyst and ionicliquid combination are subsequently separated from the reaction mixture.39. A process according to claim 1, wherein the metalfluoroalkylsulfonylated compound is generated by addition of a metal ora metal compound to a source of [N(SO₂C_(x)F_((2x+1)))₂]⁻ anion.
 40. Aprocess according to claim 39 wherein the one or more metalfluoroalkylsulfonylated compound is a metal bistriflimide compound. 41.A process according to claim 40 wherein the source of bistriflimide ionis a bistriflimide ionic liquid.
 42. A process according to claim 39wherein the metal compound is a metal halide.
 43. A process according toclaim 2 wherein the source of bistriflimide ion is a bistriflimide ionicliquid.